41 research outputs found
Phase II evaluation of MGBG in non-small cell carcinoma of the lung
One hundred and eight patients with non-small cell lung cancer were treated in a Phase II trial with MGBG at a dose of 600 mg/m 2 i.v. weekly. Partial responses were noted in 3/43 patients with adenocarcinoma and 1/40 with squamous cell carcinoma. No responses were noted in 24 patients with large cell carcinoma. Overall, the drug was reasonably well-tolerated. At this dosage and schedule, MGBG has no substantial antitumor activity for patients with non-small cell lung cancer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45128/1/10637_2004_Article_BF00180196.pd
Identification of Host Cytosolic Sensors and Bacterial Factors Regulating the Type I Interferon Response to Legionella pneumophila
Legionella pneumophila is a gram-negative bacterial pathogen that replicates in host macrophages and causes a severe pneumonia called Legionnaires' Disease. The innate immune response to L. pneumophila remains poorly understood. Here we focused on identifying host and bacterial factors involved in the production of type I interferons (IFN) in response to L. pneumophila. It was previously suggested that the delivery of L. pneumophila DNA to the host cell cytosol is the primary signal that induces the type I IFN response. However, our data are not easily reconciled with this model. We provide genetic evidence that two RNA-sensing proteins, RIG-I and MDA5, participate in the IFN response to L. pneumophila. Importantly, these sensors do not seem to be required for the IFN response to L. pneumophila DNA, whereas we found that RIG-I was required for the response to L. pneumophila RNA. Thus, we hypothesize that bacterial RNA, or perhaps an induced host RNA, is the primary stimulus inducing the IFN response to L. pneumophila. Our study also identified a secreted effector protein, SdhA, as a key suppressor of the IFN response to L. pneumophila. Although viral suppressors of cytosolic RNA-sensing pathways have been previously identified, analogous bacterial factors have not been described. Thus, our results provide new insights into the molecular mechanisms by which an intracellular bacterial pathogen activates and also represses innate immune responses
Two Genes on A/J Chromosome 18 Are Associated with Susceptibility to Staphylococcus aureus Infection by Combined Microarray and QTL Analyses
Although it has recently been shown that A/J mice are highly susceptible to Staphylococcus aureus sepsis as compared to C57BL/6J, the specific genes responsible for this differential phenotype are unknown. Using chromosome substitution strains (CSS), we found that loci on chromosomes 8, 11, and 18 influence susceptibility to S. aureus sepsis in A/J mice. We then used two candidate gene selection strategies to identify genes on these three chromosomes associated with S. aureus susceptibility, and targeted genes identified by both gene selection strategies. First, we used whole genome transcription profiling to identify 191 (56 on chr. 8, 100 on chr. 11, and 35 on chr. 18) genes on our three chromosomes of interest that are differentially expressed between S. aureus-infected A/J and C57BL/6J. Second, we identified two significant quantitative trait loci (QTL) for survival post-infection on chr. 18 using N2 backcross mice (F1 [C18A]×C57BL/6J). Ten genes on chr. 18 (March3, Cep120, Chmp1b, Dcp2, Dtwd2, Isoc1, Lman1, Spire1, Tnfaip8, and Seh1l) mapped to the two significant QTL regions and were also identified by the expression array selection strategy. Using real-time PCR, 6 of these 10 genes (Chmp1b, Dtwd2, Isoc1, Lman1, Tnfaip8, and Seh1l) showed significantly different expression levels between S. aureus-infected A/J and C57BL/6J. For two (Tnfaip8 and Seh1l) of these 6 genes, siRNA-mediated knockdown of gene expression in S. aureus–challenged RAW264.7 macrophages induced significant changes in the cytokine response (IL-1 β and GM-CSF) compared to negative controls. These cytokine response changes were consistent with those seen in S. aureus-challenged peritoneal macrophages from CSS 18 mice (which contain A/J chromosome 18 but are otherwise C57BL/6J), but not C57BL/6J mice. These findings suggest that two genes, Tnfaip8 and Seh1l, may contribute to susceptibility to S. aureus in A/J mice, and represent promising candidates for human genetic susceptibility studies
An integrated transcriptome and expressed variant analysis of sepsis survival and death
BackgroundSepsis, a leading cause of morbidity and mortality, is not a homogeneous disease but rather a syndrome encompassing many heterogeneous pathophysiologies. Patient factors including genetics predispose to poor outcomes, though current clinical characterizations fail to identify those at greatest risk of progression and mortality.MethodsThe Community Acquired Pneumonia and Sepsis Outcome Diagnostic study enrolled 1,152 subjects with suspected sepsis. We sequenced peripheral blood RNA of 129 representative subjects with systemic inflammatory response syndrome (SIRS) or sepsis (SIRS due to infection), including 78 sepsis survivors and 28 sepsis non-survivors who had previously undergone plasma proteomic and metabolomic profiling. Gene expression differences were identified between sepsis survivors, sepsis non-survivors, and SIRS followed by gene enrichment pathway analysis. Expressed sequence variants were identified followed by testing for association with sepsis outcomes.ResultsThe expression of 338 genes differed between subjects with SIRS and those with sepsis, primarily reflecting immune activation in sepsis. Expression of 1,238 genes differed with sepsis outcome: non-survivors had lower expression of many immune function-related genes. Functional genetic variants associated with sepsis mortality were sought based on a common disease-rare variant hypothesis. VPS9D1, whose expression was increased in sepsis survivors, had a higher burden of missense variants in sepsis survivors. The presence of variants was associated with altered expression of 3,799 genes, primarily reflecting Golgi and endosome biology.ConclusionsThe activation of immune response-related genes seen in sepsis survivors was muted in sepsis non-survivors. The association of sepsis survival with a robust immune response and the presence of missense variants in VPS9D1 warrants replication and further functional studies.Trial registrationClinicalTrials.gov NCT00258869. Registered on 23 November 2005.Electronic supplementary materialThe online version of this article (doi:10.1186/s13073-014-0111-5) contains supplementary material, which is available to authorized users
Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia
BACKGROUND: The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial. Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate.
OBJECTIVE: To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S. aureus bacteremia.
DESIGN: Cost-effectiveness analysis.
DATA SOURCES: MEDLINE search of literature; clinical data from patients with S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees.
TARGET POPULATION: Patients with catheter-associated S. aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices.
TIME HORIZON: Patient lifetime.
PERSPECTIVE: Societal.
INTERVENTIONS: Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy.
OUTCOME MEASURES: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios.
RESULTS OF BASE-CASE ANALYSIS: Compared with empirical short-course therapy, the TEE strategy cost 1,667,971 per QALY) was higher than that which society usually considers cost-effective.
RESULTS OF SENSITIVITY ANALYSES: In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155,624 per QALY.
CONCLUSION: Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated S. aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy
Recommended from our members
Good Studies Evaluate the Disease While Great Studies Evaluate the Patient: Development and Application of a Desirability of Outcome Ranking Endpoint for Staphylococcus aureus Bloodstream Infection.
BackgroundDesirability of outcome ranking (DOOR) is an innovative approach in clinical trials to evaluate the global benefits and risks of an intervention. We developed and validated a DOOR endpoint for Staphylococcus aureus bloodstream infection (BSI) through a survey to infectious diseases clinicians and secondary analysis of trial data.MethodsWe administered a survey of 20 cases of S. aureus BSI, asking respondents to rank outcomes by global desirability. Correlations and percentage of pairwise agreement among rankings were estimated to inform development of a DOOR endpoint, which was applied to 2 prior S. aureus BSI trials. The probability that a patient randomly assigned to experimental treatment would have a better DOOR ranking than if assigned to control was estimated. Results were also analyzed using partial credit, which is analogous to scoring an academic test, assigning 100% to the most desirable outcome, 0% to the least, and "partial credit" to intermediate ranks.ResultsForty-two recipients (97%) completed the survey. The DOOR endpoint fitting these rankings (r = 0.89; 95% confidence interval, 0.67 to 0.94) incorporated survival plus cumulative occurrence of adverse events, cure, infectious complications, and ongoing symptoms. Tailored versions of this endpoint were applied to 2 S. aureus BSI trials, and both demonstrated no benefit of the experimental treatment using DOOR and partial credit analysis.ConclusionsUsing S. aureus BSI as an exemplar, we developed a DOOR endpoint that can be used as a template for development of DOOR endpoints for other diseases. Future trials can incorporate DOOR to allow for global assessment of patient experience